Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2020

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Components of Net Periodic Benefit Cost

The components of net periodic benefit cost (credit) for the Corporation's qualified pension plan, non-qualified pension plan and postretirement benefit plan are as follows.

Qualified Defined Benefit Pension Plan	Three Months Ended March 31,
(in millions)	2020			2019
Service cost	$	8		$	8
Other components of net benefit credit:
Interest cost	18			20
Expected return on plan assets	(43		)	(42		)
Amortization of prior service credit	(5		)	(5		)
Amortization of net loss	14			9
Total other components of net benefit credit	(16		)	(18		)
Net periodic defined benefit credit	$	(8	)	$	(10	)

Non-Qualified Defined Benefit Pension Plan	Three Months Ended March 31,
(in millions)	2020			2019
Service cost	$	1		$	1
Other components of net benefit cost:
Interest cost	2			2
Amortization of prior service credit	(2		)	(2		)
Amortization of net loss	2			2
Total other components of net benefit cost	2			2
Net periodic defined benefit cost	$	3		$	3

Postretirement Benefit Plan	Three Months Ended March 31,
(in millions)	2020		2019
Other components of net benefit credit:
Interest cost	$	—	$	1
Expected return on plan assets	—		(1		)
Net periodic defined benefit credit	$	—	$	—